Motorcycles generally include an internal combustion engine that is supported by some type of frame structure. During motorcycle operation, a motorcycle engine generates various types of vibrations that have frequency and amplitude characteristics that are often dependent upon the size and type of internal combustion engine. For example, an engine having an arrangement of four cylinders in a line generates vibrations that differ in frequency and amplitude when compared to vibrations generated by an engine having two cylinders arranged in a V configuration. Depending upon the type of engine in a given motorcycle, consideration must be given to the impact the specific type of vibrations generated by that engine may have on vehicle durability, rider comfort, and other factors.
While many techniques have been developed to isolate or reduce vibrations transmitted from the engine to the rest of the vehicle, one such technique includes supporting the engine within the frame using an arrangement of resilient engine mounts. While the specifics of construction vary significantly between motorcycles, most resilient mounting systems include two or more resilient mount assemblies that cooperate to support the engine while also isolating the frame, the rider, and several other vehicle components from the vibrations generated by the engine. One example of a vibration isolation system of this type is disclosed in U.S. Pat. No. 4,776,423 (“the '423 patent”), which is incorporated by reference herein. The '423 patent discloses an isolation system having a first resilient mount assembly supporting a rear portion of the motorcycle engine, and a second resilient mount assembly supporting a forward portion of the engine.